You know how on when an intact iPhone vibrates, the vibration is fluid, kinda quiet, and suppressed? My iPhone 2G sounds much louder now when it vibrates; you can hear something akin of buzzing or rattling as if something fell loose.

The main thing that bothers me is that I plan on reselling it soon because I have an iPhone 3GS (and I'll use it once they release the bloody JB anytime now ), and I don't know if this all means the vibration module is about to crap out on me before I can sell it.

In the iPhone 2G, the buzzer is connected to a metal plate with two screws. This metal plate is glued to the metal back plate / housing at the factory. I have seen cases where these screws come loose or completely out after heavy phone usage. It's possible that one has come loose, causing the vibrator to not fit correctly. I've never seen the glue come loose by itself, but I suppose this is also possible. Your only option is to crack the iPhone open and check the screws. I don't recommend this on the 2G as it's VERY easy to damage the metal back plate / housing unless you have a lot of experience and know exactly where the pressure points are. I would sell it as-is and just make sure you give an accurate description. That way your buyer will be happy and you can avoid chargebacks, negative feedback, etc. You could have a local iPhone repair shop put another back on it, but you're probably looking at around $50 for that service. Not really worth it when the phone is worth, at most, $225. I hope that helps!